Measuring cardiac output in children undergoing cardiac catheterization: comparison between the Fick method and PRAM (pressure recording analytical method)

Cardiac output monitoring in children: a review

Cardiac output monitoring enables physiology-directed management of critically ill children and aids in the early detection of clinical deterioration. Multiple invasive techniques have been developed and have demonstrated ability to improve clinical outcomes. However, all require invasive arterial or venous catheters, with associated risks of infection, thrombosis and vascular injury. Non-invasive monitoring of cardiac output and fluid responsiveness in infants and children is an active area of interest and several proven techniques are available. Novel non-invasive cardiac output monitors offer a promising alternative to echocardiography and have proven their ability to influence clinical practice. Assessment of perfusion remains a challenge; however, technologies such as near-infrared spectroscopy and photoplethysmography may prove valuable clinical adjuncts in the future.

The predictive value of pressure recording analytical method for the duration of mechanical ventilation in children undergoing cardiac surgery with an XGBoost-based machine learning model

Objective

Prolonged mechanical ventilation in children undergoing cardiac surgery is related to the decrease in cardiac output. The pressure recording analytical method (PRAM) is a minimally invasive system for continuous hemodynamic monitoring. To evaluate the postoperative prognosis, our study explored the predictive value of hemodynamic management for the duration of mechanical ventilation (DMV).

Methods

This retrospective study included 60 infants who underwent cardiac surgery. Cardiac index (CI), the maximal slope of systolic upstroke (dp/dt_max), and cardiac cycle efficiency (CCE) derived from PRAM were documented in each patient 0, 4, 8, and 12 h (T0, T1, T2, T3, and T4, respectively) after their admission to the intensive care unit (ICU). A linear mixed model was used to deal with the hemodynamic data. Correlation analysis, receiver operating characteristic (ROC), and a XGBoost machine learning model were used to find the key factors for prediction.

Results

Linear mixed model revealed time and group effect in CI and dp/dt_max. Prolonged DMV also have negative correlations with age, weight, CI at and dp/dt_max at T2. dp/dt_max outweighing CI was the strongest predictor (AUC of ROC: 0.978 vs. 0.811, p < 0.01). The machine learning model suggested that dp/dt_max at T2 ≤ 1.049 or < 1.049 in combination with CI at T0 ≤ 2.0 or >2.0 can predict whether prolonged DMV (AUC of ROC = 0.856).

Conclusion

Cardiac dysfunction is associated with a prolonged DMV with hemodynamic evidence. CI measured by PRAM immediately after ICU admission and dp/dt_max 8h later are two key factors in predicting prolonged DMV.

Renal tissue desaturation and acute kidney injury in infant cardiac surgery: a prospective propensity score-matched cohort study

BACKGROUND

Previous studies on the association between renal tissue desaturation and acute kidney injury (AKI) in infant cardiac surgery are limited by small sample sizes and inconsistent results. This prospective study aimed to determine the association between renal desaturation and AKI in infants undergoing surgical repair of an isolated ventricular septal defect (VSD).

METHODS

Infants undergoing VSD repair involving cardiopulmonary bypass participated in this prospective cohort study. The exposure of interest was renal tissue desaturation, defined as at least 20% decrease in saturation from baseline for at least 60 consecutive seconds. Intraoperative care was not guided by renal oxygenation, as the anaesthesiologists were blinded to the monitor. The outcome was AKI arising within postoperative Days 1-3. The primary analysis was based on propensity score-matched infants with and without intraoperative renal desaturation.

RESULTS

Intraoperative renal desaturation was detected in 38 of 242 infants using near-infrared spectroscopy. This group of infants was matched with 114 infants without intraoperative renal saturation after propensity score matching. Acute kidney injury occurred in 47% (18/38) and 27% (31/114) of infants with or without renal desaturation, respectively. Infants with renal desaturation had higher odds of developing AKI than infants without renal desaturation based on conditional logistic regression (odds ratio 2.79; 95% confidence interval: 1.21-6.44; P=0.016). The cumulative time of renal desaturation correlated moderately with the ratio of postoperative peak creatinine to preoperative baseline creatinine (r=0.51; P<0.001).

CONCLUSIONS

Intraoperative renal desaturation is associated with increased odds of developing AKI after surgical repair of an isolated VSD involving cardiopulmonary bypass in infants.

CLINICAL TRIAL REGISTRATION

NCT03941015.

A clinical-in silico study on the effectiveness of multipoint bicathodic and cathodic-anodal pacing in cardiac resynchronization therapy

Up to one-third of patients undergoing cardiac resynchronization therapy (CRT) are nonresponders. Multipoint bicathodic and cathodic-anodal left ventricle (LV) stimulations could overcome this clinical challenge, but their effectiveness remains controversial. Here we evaluate the performance of such stimulations through both in vivo and in silico experiments, the latter based on computer electromechanical modeling. Seven patients, all candidates for CRT, received a quadripolar LV lead. Four stimulations were tested: right ventricular (RVS); conventional single point biventricular (S-BS); multipoint biventricular bicathodic (CC-BS) and multipoint biventricular cathodic-anodal (CA-BS). The following parameters were processed: QRS duration; maximal time derivative of arterial pressure (dPdt_max); systolic arterial pressure (P_sys); and stroke volume (SV). Echocardiographic data of each patient were then obtained to create an LV geometric model. Numerical simulations were based on a strongly coupled Bidomain electromechanical coupling model. Considering the in vivo parameters, when comparing S-BS to RVS, there was no significant decrease in SV (from 45 ± 11 to 44 ± 20 ml) and 6% and 4% increases of dPdt_max and P_sys, respectively. Focusing on in silico parameters, with respect to RVS, S-BS exhibited a significant increase of SV, dPdt_max and P_sys. Neither the in vivo nor in silico results showed any significant hemodynamic and electrical difference among S-BS, CC-BS and CA-BS configurations. These results show that CC-BS and CA-BS yield a comparable CRT performance, but they do not always yield improvement in terms of hemodynamic parameters with respect to S-BS. The computational results confirmed the in vivo observations, thus providing theoretical support to the clinical experiments.

Contemporary Trends and Risk Factors of Hemodynamic and Myocardial Mechanics Derived by the Pressure Recording Analytical Method After Pediatric Cardiopulmonary Bypass

Objective: Adverse factors of postoperative hemodynamic and myocardial performance remain largely unexplored in children with congenital heart disease following cardiopulmonary bypass due to technical limitations. Pressure recording analytical method (PRAM) is a continuous hemodynamic and myocardial performance monitoring technique based on beat-to-beat arterial pressure waveform. Using PRAM, we examined the temporal trends and adverse factors, in clinical management, of these performances.

Methods: We monitored blood pressure, cardiac index, cardiac cycle efficiency (CCE), dP/dT_max, and systematic vascular resistance index in 91 children (aged 186 ± 256 days) during their first 48 h after cardiopulmonary bypass. Above parameters, inotropic and vasoactive drug dosages, and serum lactate were recorded 3-hourly. NT-proBNP was measured daily.

Results: CCE and dP/dT_max gradually increased (Ps < 0.0001), while systematic vascular resistance index, diastolic blood pressure and inotrope dosages decreased (Ps < 0.0001) over time. Cardiac index, systolic blood pressure, and heart rate did not change significantly (Ps ≥ 0.231). Patients undergoing deep hypothermic circulatory arrest had significantly higher heart rate and lower CCE (Ps ≤ 0.006) over time. Multivariate analyses indicated that epinephrine dose significantly correlated with systolic blood pressure, cardiac index, CCE, and dP/dT_max after polynomial transformation, with the peak ranging from 0.075 to 0.097.

Conclusions: Systemic hemodynamic and myocardial performance gradually improved in the first 48 h after cardiopulmonary bypass without the “classic” nadir at 9–12 h. Deep hypothermic circulatory arrest and higher epinephrine doses were adversely associated with these performances. CCE, rather than cardiac index or other common-used parameters, was the most sensitive and consistent indicator.

Cardiac Output Evaluation on Septic Shock Patients: Comparison between Calibrated and Uncalibrated Devices during Vasopressor Therapy

There are no reliable, non-invasive methods to accurately measure cardiac output (CO) in septic patients. MostCare (Vytech Health™, Vygon, Padova, Italy), is a beat-to-beat, self calibrated method for CO measurement based on continuous analysis of reflected arterial pressure waveforms. We enrolled 40 patients that were suffering from septic shock and requiring norepinephrine infusion to target blood pressure in order to to evaluate the level of agreement between a calibrated transpulmonary thermodilution device (PiCCO System, Pulsion Medical Systems, Feldkirchen, Germany) and the MostCare system in detecting and tracking changes in CO measurements related to norepinephrine reduction in septic shock patients,. PiCCO was connected to a 5 Fr femoral artery catheter and to a central venous catheter. System calibration was performed with 15 mL of cold saline injection over about 3 s. The MostCare device was connected to the artery catheter to analyze the arterial waveform. Before reducing norepinephrine infusion, the PiCCO system was calibrated, the MostCare waveform was optimized, and the values of the complete hemodynamic profile were recorded (T1). Norepinephrine infusion was then reduced by 0.03 mcg/Kg/min. After 30 min, a new calibration of PiCCO system and a new record on both monitors were performed (T2). Static measurements agreements were assessed using the Bland-Altman test, while trending ability was investigated using polar plot analysis. If volume expansion occurred, then related data were separately analyzed. At T1 mean the CO was 5.38 (SD 0.60) L/min, the mean difference was 0.176 L/min, the limits of agreement (LoA) was +1.39 and -1.04 L/min, and the percentage error (PE) was 22.6%; at T2 the mean CO was 5.44 (SD 0.73) L/min, the mean difference was 0.053 L/min, the LoA was +1.51 and -1.40, and the PE was 27%. After considering the volume expansion between T1 and T2, the mean CO at T1 was 5.39 L/min (SD 0.47), the LoA was +1.09 and -0.78 L/min, and the percentage error (PE) was 17%; at T2 the mean CO was 5.35 L/min (SD 0.81), the LoA was +1.73 and -1.52 L/min, and the PE was 30%. The polar plot diagram seems to confirm the trending ability of MostCare system versus the reference method. In septic patients, when the arterial waveform is accurate, MostCare and PiCCO transpulmonary thermodilution exhibit good agreement even after the reduction of norepinephrine and changes in vascular tone or volume expansion. MostCare could be a rapid to set, reliable, and useful tool to monitor hemodynamic variations in septic patients in emergency contexts where thermodilution methods or other advanced systems are not easily available.

Prediction of Fluid Responsiveness by Stroke Volume Variation in Children Undergoing Fontan Operation

Background

Fontan operation is a palliative medical procedure performed on children with single-ventricle defects. As postoperative success of the procedure largely depends on the preload volume, it is necessary to maintain an appropriate pressure gradient between the systemic vein and the left atrium to ensure the effective volume of systemic circulation. However, there is a lack of effective indexes to evaluate fluid responsiveness in Fontan patients. Stroke volume variation (SVV) is a dynamic hemodynamic parameter based on cardiopulmonary interaction in mechanical ventilation. This study is aimed at validating the sensitivity and specificity of SVV and central venous pressure (CVP) in assessing the fluid responsiveness of Fontan patients.

Method

Sixty-four children with single ventricle who underwent modified Fontan operation between May 2018 and January 2020 were included in this study. Patients were administered 10 ml·kg⁻¹ albumin for fluid challenge within 10 min after cardiopulmonary bypass. Before and after fluid challenge, the invasive arterial pressure module was connected to MostCare™ equipment to collect the cardiac index (CI) and SVV dynamically in a time window of 30 s at a frequency of 1000 Hz. According to the range of CI change, patients with ΔCI ≥ 15% were classified into the responder (R) group and those with ΔCI < 15% into the nonresponder (NR) group. Using SVV and CVP as indicators, the receiver operating characteristic (ROC) curve of the patients was established, and the area under curve (AUC), diagnostic threshold, sensitivity, and specificity were calculated.

Results

The SVV values were 16.28% (25th and 75th percentiles 14.17%-19.24%) and 13.68% (25th and 75th percentiles 12.90%-15.89%) before and after fluid challenge treatment in responders, respectively, and the values were 18.60 ± 1.83 mmHg before and 20.20 ± 2.39 mmHg for CVP after treatment. The AUC of SVV was 0.74 (95% confidence interval (CI) 0.54-0.94, P < 0.05), and the cutoff value was 16%, offering a sensitivity of 50% and a specificity of 91.7%. Meanwhile, the AUC of CVP was 0.70 (95% CI 0.50-0.92, P > 0.05), and the cutoff value was 19.5 mmHg, offering a sensitivity of 58% and a specificity of 76%.

Conclusion

SVV exhibited a good predictive value for fluid responsiveness in pediatric Fontan patients. Appropriate fluid therapy according to SVV could improve the cardiac function of such patients. Trial registration. This study was registered in Chinese Clinical Trail Registry on Jan 26, 2018. Registration number is ChiCTR1800014654. Registry URL is http://www.chictr.org.cn/showproj.aspx?proj=25019. This observational prospective study was approved by the Local Ethics Committee of Shanghai Children's Medical Center affiliated to Shanghai Jiao Tong University (SCMCIRB-K2017035).

Advanced Hemodynamic Monitoring in the Neonatal Intensive Care Unit

Clinical assessment of cardiac output by interpretation of indirect parameters has proven to be inaccurate, irrespective of the level of experience of the clinician. Objective cardiac output monitoring is feasible in newborn infants in intensive care. The most promising methods include transthoracic echocardiography, transcutaneous Doppler, electrical biosensing technologies, transpulmonary ultrasound dilution, and arterial pulse contour analysis. Simultaneous assessment of blood pressure and cardiac output enables the identification of the earliest stage of shock. Comprehensive hemodynamic monitoring is pivotal for an individualized pathophysiology-based hemodynamic management.

Prognostic value of cardiac cycle efficiency in children undergoing cardiac surgery: a prospective observational study

BACKGROUND

Cardiac cycle efficiency (CCE) derived from a pressure-recording analytical method is a unique parameter to assess haemodynamic performance from an energetic view. This study investigated changes of CCE according to an anatomical diagnosis group, and its association with early postoperative outcomes in children undergoing cardiac surgery.

METHODS

Ninety children were included with a ventricular septal defect (VSD; n=30), tetralogy of Fallot (TOF; n=40), or total anomalous pulmonary venous connection (TAPVC; n=20). CCE along with other haemodynamic parameters, was recorded from anaesthesia induction until 48 h post-surgery. Predictive CCE (CCE_p) was defined as the average of CCE at post-modified ultrafiltration and CCE at the end of surgery. The relationship between CCE and early outcomes was assessed by the comparison between the high-CCE_p group (CCE_p ≥75th centile) and the low-CCE_p group (CCE_p ≤25th centile).

RESULTS

There was a significant time × diagnostic group interaction effect in the trend of CCE. Compared with the high-CCE_p group (n=23), the low-CCE_p group (n=22) required more inotropics post-surgery, had higher lactate concentrations at 8 and 24 h post-surgery, a longer intubation time and longer ICU stay, and higher frequency of peritoneal fluid.

CONCLUSIONS

Perioperative changes of CCE vary according to anatomical diagnosis in children undergoing cardiac surgery. Children with TOF have an unfavourable trend of CCE compared with children with VSD or TAPVC. A decline in CCE is associated with adverse early postoperative outcomes.

CLINICAL TRIAL REGISTRATION

ChiCTR1800014996.

Comparison between Pressure Recording Analytical Method and Fick Method to Measure Cardiac Output in Pediatric Cardiac Surgery

Background:

There is an increased interest in methods of objective cardiac output measurement in pediatric cardiac surgery. Several techniques are available, but have limitations, among the new technologies pressure recording analytical method with MostCare (MostCare-PRAM), a minimally invasive hemodynamic monitoring system, represents a novel arterial pulse contour method that does not require calibration. For this reason, we compared the MostCare-PRAM vs the Fick method for estimation of cardiac output.

Methods:

We studied prospectively 13 pediatric patients who underwent cardiac surgery and compared intraoperatively Cardiac Index (CI) measured with the MostCare-PRAM with the CI measured with the Fick method. We also measured Cardiac Cycle Efficiency (CCE) and maximal arterial pressure/time ratio (dp/dt max) and compared with Fick method.

Results:

The data showed good agreement between CI Fick and CI MostCare-PRAM (r = 0.93 and R2= 0.86; p < 0.0001) and also between CCE (r = 0.82 and R2 = 0.67; p < 0.001) and dp/dt (r = 0.84; R2 = 0.81; p < 0.001) with CI measured with Fick method.

Conclusion:

In pediatric patients submitted to cardiac surgery, the MostCare-PRAM seems to estimate CI with a good level of agreement with the Fick method measurements.

Comparison of hemodynamic effects of sevoflurane and ketamine as basal anesthesia by a new and direct monitoring during induction in children with ventricular septal defect: A prospective, randomized research

BACKGROUND

Sevoflurane and ketamine are commonly used to obtain sedation and facilitate intravenous anesthetic induction in children undergoing cardiac surgery who are uncooperative. We used a new and direct systemic hemodynamic monitoring technique pressure recording analytical method and compared the hemodynamic effects of sevoflurane and ketamine to facilitate intravenous anesthetic induction.

METHODS

Forty-four children with ventricular septal defect (2.2 ± 1.2 years) were enrolled and randomized to receive sevoflurane (Group S) or intramuscular ketamine (Group K) for sedation, followed by intravenous midazolam-sufentanil induction and tracheal intubation. Recorded parameters included heart rate (HR), arterial pressures, stroke volume index (SVI), cardiac index (CI), systemic vascular resistance index (SVRI), the maximal slope of systolic upstroke (dp/dtmax) after sedation obtained with sevoflurane or ketamine, 1, 2, 5 minutes after midazolam-sufentanil, 1, 2, 5, and 10 minutes after tracheal intubation. Rate-pressure product (RPP) and cardiac power output (CPO) were calculated.

RESULTS

As compared with Group S, Group K had faster decreases during intravenous anesthetic induction in arterial pressures (P < .01 for all), higher HR, arterial pressures, SVRI, dp/dtmax, RPP, lower SVI, CI, CPO (P < .05 for all) during the study period.

CONCLUSION

As compared with sevoflurane, ketamine facilitated intravenous anesthetic induction exerts unfavorable effects on systemic hemodynamic and myocardial energetic in children with ventricular septal defect.